A multitude of designs have been proposed for rotary internal combustion engines over the years and yet, despite the multiplicity of such rotary designs, and despite the obvious advantages of the unidirectional movement inherent in the rotary design, the reciprocating variety of engine continues to account for the vast majority of internal combustion engines sold. This presumably is because the various rotary designs proposed have either been too complex to manufacture on a large scale, have been inefficient in operation, have required an inordinate amount of maintenance, or have had a relatively short product life.
This invention relates to a rotary internal combustion engine of the type in which two rotating pistons or vanes are connected to concentric shafts or hubs with the leading and following pistons rotating in a manner that allows the pistons to alternately approach and move away from each other to permit the intake of a combustible fuel mixture, its compression, ignition, expansion and exhaust. Prior art rotary internal combustion engines of this type have suffered from an inability to convert the somewhat promiscuous and seemingly random movement of the two pistons into a predictable, usable movement of an output shaft. Prior art attempts to provide a predictable or usable movement of the output shaft have involved the attempted use of a predetermined program to control the compression and expansion strokes wherein a fixed program of motion between the pistons is established by the use of cams, lobes, planetary gears, cranks, grooves, slots, rollers or other similar linkages. However, these prior art attempts to provide a predictable, usable movement of the output shaft by providing a predetermined fixed program of motion between the pistons have been unsuccessful since they have generated uncompensated stresses which have tended to literally tear the engine apart. They have also resulted in engine designs that are unduly complex, unduly expensive to manufacture, and which require an inordinate amount of maintenance.
A rotary internal combustion engine overcoming many of these problems with the prior art rotary internal combustion engine designs is disclosed in applicant's copending patent application Ser. No. 773,636. The engine of that application includes a housing; a first piston or vane mounted for rotation in the housing on a fixed axis; a second piston or vane mounted for rotation in the housing on the fixed axis independently of the first vane; means precluding rotation of either vane in one direction about the axis while allowing free rotation in the other direction about the axis so that the vanes may rotate freely in the other direction and may simultaneously undergo relative rotation; and converter means, including an output shaft, drivingly connected to the vanes and operative to convert the rotation of the vanes in such other direction as well as the relative rotation of the vanes into a unidirectional, steady speed rotation of the output shaft of the converter means. Whereas this engine design eliminates many of the problems of the prior art rotary internal combustion engines, the means provided to confine the rotation of the vanes to a single direction may, in certain applications, generate undesirable engine vibration because of the reaction forces being absorbed by the rotation confining means.